Set-Cover Approximation Algorithms for Load-Aware Readers Placement in RFID Networks

Radio Frequency Identification (RFID) is an emerging wireless network technology that poses new fundamental challenges. One such challenge is coverage in RFID networks which is the ability to accurately read a set of RFID tags. Accurate coverage is of utmost importance in RFID networks as missing some tags may result in missing important events and, for some RFID applications, losing asset and revenue. In this paper, we address an optimization problem related to the deployment of RFID readers to cover a set of RFID tags with the objectives of minimizing the number of readers, reducing overlapping among readers coverage and balancing the load. We propose a set-cover based approximation algorithm for RFID coverage with the minimum number of readers. We extend this algorithm to consider the objective of reducing overlap and interference among readers interrogation ranges. And finally, we devise a load balancing algorithm that evenly distributes the load among different readers. Comprehensive experiments that study the performance of our algorithms are presented.